[en] This work provides a detailed description of a complete PC-Windows controlled Langmuir probe system developed to allow the acquisition and analysis of data from a plasma. The system was developed for application in radio frequency (rf) and pulsed rf plasmas. The operational system consists of a personal computer (PC), electronic hardware, Windows-based software, purpose-specific written here and a selection of rf probes. In use a probe is immersed in a plasma under vacuum and used to collect data from the plasma which is then passed through the electronics and back to the PC. The electronics provide an interface between the PC and the probe, giving digital-to-analogue and analogue-to-digital conversion to allow data to be exchanged. The electronics also allow probe voltages of ±130V to be generated and the collection and amplification of current from the probe. The software controls the operation of the electronics, allowing plasma data to be collected and displayed graphically on the PC screen. To facilitate system test and calibration the software also provides a selection of hardware calibration and self-diagnostic routines. The software in addition has plasma analysis capabilities, i.e. it calculates the plasma parameters and generates the electron energy distribution function (eedf) from the data collected for a given plasma. Overall system operation was verified using rf argon and nitrogen plasmas; argon and nitrogen eedfs were obtained which agree well with comparable literature data and results. Results from a series of experiments in pulsed rf argon and nitrogen plasmas are also presented. (author)